Camshaft support and crankcase air vent for an engine

ABSTRACT

A cam support plate and an air venting cover plate for an internal combustion engine are provided along with a gasket to seal the oil passages between the cam support plate and the cam chest. The cam support plate provides a rigid, generally non flexing support for mounting one or more cam shafts and crankshafts for an internal combustion engine. The cam support plate also provides appropriate mounting and oil circulating paths as required by the engine. A cover plate is provided which is not decorative but rather functional, includes a number of chambers having chamber walls of varying depths to provide a labyrinth or serpentine like path for air to separate from the oil and vent to the outside atmosphere through a hole in the plate and or cover. Grooves or slots provided in the lower region of the chambers allow the oil separated from the air to drain back into the crankcase.

TECHNICAL FIELD

The present invention relates to internal combustion engines and moreparticularly, relates to a support plate, cam cover and gasket systemproviding distortion free support for an engine's cam-shaft andcrankshaft and oil pump while simultaneously providing an air vent forthe engine crankcase to reduce excessive oil temperature, crankcasepressure, oil foaming and aeration

BACKGROUND INFORMATION

Internal combustion engines such as motorcycle engines, for example,typically have two or more cylinders and each cycle is synchronized witha camshaft. Each camshaft is supported at one end by the engine housingand at the other end by a support plate of some sort. An example of suchan engine and arrangement of parts can be seen, for example, in U.S.Pat. No. 6,047,667 incorporated herein by reference.

In many instances, however, the support plate for the camshaft in suchsystems is either more decorative than anything and/or provides littlesupport for the camshaft(s) and crankshaft. It has been found that a camsupport plate (often called a cam plate) that is not rigid enough allowsa shift or bending action often causing scoring or other damage to theoil pump. The lack of rigidity in the cam plate also adds to oil leakingby mating passages due to flexing of the cam plate in its central regionin an area where oil seals or no seals at all are generally found.

An additional problem arises in internal combustion engines that utilizea sump oil passage located in the bottom region of the crankcase. Insuch systems, piston pressure on the down stroke is needed to help movethe oil to the oil pump and then back to the reservoir (oil tank).Normally a neutral pressure or slight pressure in the crankcase from thepistons allows oil to drain from the top end of the engine to thecrankcase. A significant problem arises as an engine's rpms ordisplacement increases in that as pressure increases in a closedcompartment (generally termed crankcase), the crankcase remainspressurized on both strokes. At this point, the oil is not allowed tofreely drain from the top end to the crankcase, which causes the oil tobecome super heated in the heads. As rpm's decrease the pressure in thecrankcase also decreases and the super heated oil can drain into thecrankcase. This super heated oil is then pushed to the oil pump on thepiston's down stroke. Because of the excess heat in the engine oil, airis easily introduced into the oil and the oil becomes aerated. Thisaerated oil is pushed from the oil pump to the reservoir (oil tank).This aerated oil is then fed back into the engine via the oil pump,reducing lubricity and hydrology to the internal engine components.

SUMMARY

Accordingly, what is needed is an external cam support plate whichprovides significant rigidity for the camshaft(s) and crankshaft, whichincludes a cam plate cover that includes an air baffle path that housesa labyrinth of passages vented externally through the cam support plateand/or cam cover allowing air and oil to be separated. Pressuregenerated by the pistons cause the excess pressure in the crankcase tobe vented to atmosphere or to the air cleaner backing plate for emissionpurposes. This in turn allows the oil to drain freely from the top endof the engine, keeping the oil cooler and more viscous. This cooler oilcan be pushed to the pump and back to the reservoir (oil tank) whilesubstantially reducing the amount of air and temperature in the oil.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reading the following detailed description, takentogether with the drawings wherein:

FIG. 1 is left side perspective view of the camshaft support plate,sealing gaskets and air venting cover according to the present inventionin position to be mounted to an engine;

FIG. 2 is right side perspective view of the camshaft support plate,sealing gaskets and air venting cover according to the present inventionin position to be mounted to an engine;

FIG. 3 is an interior perspective view of the air venting coveraccording to the present invention;

FIG. 4 is an exterior perspective view of the air venting coveraccording to the present invention; and

FIG. 5 is a close up interior perspective view of the air venting coveraccording to the present invention illustrating a cover for the air ventlabyrinth area.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention features a novel camshaft support and crankcaseair vent including one or more gaskets 11, FIG. 1, a camshaft supportplate 10 (also called cam plate), and an air venting cover 12 for use onan internal combustion engine 14 such as, for exemplary purposes only, amotorcycle engine. Although the present invention will be explained inconnection with a motorcycle engine, this is not a limitation of thepresent invention as the invention may be utilized on many differenttypes of internal combustion engines.

The cam plate 10 includes one or more openings 16 in which are mountedcamshaft's and one or more openings 18 in which is supporting acrankshaft. Other openings, holes and channels are provided in the camplate as necessary to fasten the cam plate 10 to the engine block andprovide appropriate oil movement throughout the engine's crank case, asis well known in the art.

As shown in FIGS. 1 and 2, the cam plate 10 as a first thicknessindicated generally by arrows 16 along a portion of the periphery of thecam plate as well as in the central region 18. The first thickness istypically in the range of 0.600″ to 1.000″ inches thick. The cam plate10 is made out of a solid piece of aluminum which is machined asappropriate and necessary. The cam plate 10 also includes a portionhaving a second thickness 20 greater than the first thickness 16. In thepreferred embodiments, the second thickness 20 is in the range of 0.900″to 1.000″ inches thick.

In a similar fashion, the air venting cover 12 is machined out of asolid piece of aluminum although it could also be fabricated from twopieces of aluminum which joined together to perform the same function.

As shown in greater detail in FIG. 3, the air venting cover 12 includesan interior region 22 having a number of cavities which are sized andshaped to accommodate the needs of various engine sizes, as is wellknown in the art. One unique feature of the present invention includes anumber of chambers 24 a-24 d which together form a elaborate labyrinthfor allowing air to separate from the oil in the crankcase and vent tothe atmosphere outside of the engine. Each chamber includes a wall 25separating one chamber from the next. Each chamber wall 25 includes afirst periphery region 28 which extends above or beyond a secondperiphery region 26. Thus, the recessed region 26 in each chamber wall25 forms a serpentine or labyrinth air path 30, FIG. 5 in which air canseparate from the oil and exit through a port or opening 32 to theatmosphere. In addition, each chamber 24 includes a cut out region 34proximate the bottom of the chamber which allows the oil from whichthere has been separated, to drain back into the crankcase to bere-circulated. A thin cover plate 36 is provided to cover the chambers24 and isolate them from the rest of the crankcase so that the air andoil can efficiently separate from one another.

As shown in FIG. 4, the air vent cover 12 includes an exterior surface38 which although appears to the user to be simply decorative in natureto match other crankcase covers found on standard engines, actuallydisguised is the fact that in the interior of the cover, and innovativeair and oil separator labyrinth is provided, therefore making itfunctional.

The present invention is not intended to be limited to a system ormethod which must satisfy one or more of any stated or implied object orfeature of the invention and should not be limited to the preferred,exemplary, or primary embodiment(s) described herein. Modifications andsubstitutions by one of ordinary skill in the art are considered to bewithin the scope of the present invention, which is not to be limitedexcept by the allowed claims and their legal equivalents.

1. Parts for an engine, said engine including an engine body having acrankshaft, at least one cam shaft, at least one oil pump and at leastone oil path for circulating oil within said engine body, said engineparts comprising: a cam support plate, configured for coupling to saidengine body and for providing generally non-flexing support for said atleast one cam shaft and said crankshaft; and an engine cover, configuredfor coupling to said cam support plate, and including an engine oil/airseparator region, coupled to said at least one oil path and to an areaoutside said engine body, for allowing oil to be separated from anoil/air mixture, for allowing said oil to drain into said engine bodyand for allowing said air separated from said engine oil to vent to anarea outside said engine body.
 2. The parts for an engine of claim 1,wherein said air separated from said engine oil is vented to outsideatmosphere.
 3. The parts for an engine of claim 1, wherein said airseparated from said engine oil is vented to an air capture system. 4.The parts for an engine of claim 1, wherein said engine is an internalcombustion engine.
 5. The parts for an engine of claim 4, wherein saidinternal combustion engine is a motorcycle engine.
 6. The parts for anengine of claim 1, further including a first gasket coupled between saidcam support plate and said engine body and a second gasket coupledbetween said engine cam support plate and said engine cover.
 7. Theparts for an engine of claim 1, wherein said engine oil/air separatorregion includes an air/oil path in the form of a labyrinth.
 8. The partsfor an engine of claim 7, wherein said labyrinth includes at least onepath for air to vent to atmosphere and at least one path for oil todrain from said engine oil/air separator region to a central region insaid engine body to be pumped by said oil pump.
 9. Parts for amotorcycle engine, said motorcycle engine including an engine bodyhaving at least one cam shaft, a crankshaft, at least one oil pump andat least one oil path for circulating oil within said engine body, saidengine parts comprising: a cam support plate, configured for coupling tosaid engine body and for providing generally non-flexing support for atleast one cam shaft and said crankshaft; an engine cover, configured forcoupling to said cam support plate, and including an engine oil/airseparator region, coupled to said at least one oil path and to an areaoutside said engine body, for allowing oil to be separated from anoil/air mixture, for allowing said oil to drain into said engine bodyand for allowing said air separated from said engine oil to vent to anarea outside said engine body; and a first gasket coupled between saidcam support plate and said engine body and a second gasket coupledbetween said engine cam support plate and said engine cover.
 10. Theparts for an engine of claim 7, wherein said engine oil/air separatorregion includes an oil/air path in the form of a labyrinth.
 11. Theparts for an engine of claim 8, wherein said labyrinth includes at leastone path for air to vent to atmosphere and at least one path for oil todrain from said engine oil/air separator region to a central region insaid engine body to be pumped by said oil pump.
 12. Parts for amotorcycle engine, said motorcycle engine including an engine bodyhaving at least one cam shaft, crankshaft, at least one oil pump and atleast one oil path for circulating oil within said engine body, saidengine parts comprising: a cam support plate, configured for coupling tosaid engine body and for providing generally non-flexing support forsaid leased one cam shaft and crankshaft; an engine cover, configuredfor coupling to said cam support plate, and including an engine oil/airseparator region, coupled to said at least one oil path and to an areaoutside said engine body, for allowing oil to be separated from anoil/air mixture, for allowing said oil to drain into said engine bodyand for allowing said air separated from said engine oil to vent to anarea outside said engine body, wherein said engine oil/air separatorregion includes an oil/air path in the form of a labyrinth, saidlabyrinth including at least one path for air to vent to atmosphere andat least one path for oil to drain from said engine oil/air separatorregion to a central region in said engine body to be pumped by said oilpump; and a first gasket coupled between said cam support plate and saidengine body and a second gasket coupled between said engine cam supportplate and said engine cover.